A large plume of Saharan dust will pass over South Florida this weekend, limiting the chances of showers and ramping up the colors of sunrises and sunsets, the National Weather Service said.
The dust is normal for this time of year, as African monsoons push dry air off of North Africa and across the Atlantic. The dry air cramps stormy weather, and carries particles that refract brilliant orange and red hues as the sun rises and sets.
Despite the dust, there is still a 60% chance of precipitation each day this weekend, and the heat index temperatures over the region will remain in the triple digits.
The chances of showers and thunderstorms could increase next week, said forecasters. Additionally, there’s a moderate chance of excessive heat through Wednesday of next week.
Saharan dust, and the dry air that carries it, can hinder hurricane formation.
7/18 at 11:15am: We can view the approaching plume of Saharan Dust in real-time by using@NOAASatellites (GOES-East). 🛰️📡
Anticyclonic flow around the base of an expansive Bermuda High (H symbol) will bring the plume to South Florida this weekend. https://t.co/JxbG0JSPPm pic.twitter.com/dFFn4BcMay
— NWS Miami (@NWSMiami) July 18, 2024
“Hurricanes and tropical systems require adequate moisture for cloud formation,” said Robert Molleda of the National Weather Service, “which is what helps to provide the energy for these storms to form. If you have a layer of dry warm air, that can limit potential tropical storms from forming or intensifying.”
The dry air can kneecap storms in another way, too.
The National Oceanic and Atmospheric Administration said that the Saharan air layer that carries the dust is traveling at a brisk 25 to 55 mph — fast enough for its wind shear to knock a storm off balance.
The dry blast “can cause tilting of the tropical cyclone vortex with height and can weaken the storm’s internal heat engine,” said NOAA.
Climate researcher Brian McNoldy with the University of Miami’s Rosenstiel School of Marine, Atmospheric, and Earth Science said not only does the dry air curtail hurricane formation, but if it’s a fairly thick plume, it actually absorbs a decent fraction of the sun’s energy before that energy reaches the ocean and heats it. In other words, the dust, if thick enough, can help the oceans cool a bit, and make hurricanes in the remainder of July less likely.
